1. Field of the Invention
The present invention relates to a roller feeder and, more particularly, to a roller parallelism adjustment structure, which enables the user to adjust the transfer roller and impression roller of the roller feeder to a parallel status for accurate transfer of materials.
2. Description of the Related Art
Following fast development of technology, people require more than the old concept of “workable” when buying or using a device. To survive in market competition, manufacturers shall have to provide products with less manufacturing cost having added values.
Taiwan Patent Publication No. 529540 discloses a roller feeder entitled “Improved Structure of Roller Feeder”. According to this design, the roller feeder comprises a machine base 1, a transfer roller 2, an adjustment block 3, an impression roller 4, a release mechanism 5, and a digital-control power unit 6. The transfer roller 2 is pivotally mounted in the bottom side of the machine base 1. The impression roller 4 is pivotally mounted in the adjustment block 3 and rotatable by the transfer roller 2. The adjustment block 3 has an eccentric shaft 31 pivotally mounted between the two sidewalls 11 of the machine base 1. A hand wheel 32 is fastened to one end of the eccentric shaft 31. The user can rotate the hand wheel 32 to adjust the position of the adjustment block 3, so as to further adjust the pitch between the impression roller 4 and the transfer roller 2 subject to the thickness of the material E. During operation of the roller feeder, the digital-control power unit 6 is controlled to drive a transmission belt 63 to rotate the transfer roller 2 and the impression roller 4, so as to transfer the fed material. The transfer roller 2 and the impression roller 4 must be kept in parallel so that fed material can be accurately transferred to the processing machine for further processing. However, due to installation error or processing error (processing precision problem) of the transfer roller and the impression roller, the transfer roller and the impression roller may not be maintained in parallel perfectly, thereby resulting in a material transferring problem.